Reação de linhagens de feijoeiro ao fungo Fusarium oxysporum f. sp. phaseoli em condições controladas / Reaction of common bean lines to Fusarium oxysporum f. sp. phaseoli in controlled conditions

Entre os patógenos que mais contribuem para a redução da produtividade do feijoeiro no Brasil está o Fusarium oxysporum f. sp. phaseoli. O emprego de cultivares resistentes é o controle mais eficaz para esse patógeno. Conduziu-se este trabalho, com o objetivo de avaliar linhagens de feijoeiro (Phaseolus vulgaris L.) do banco de germoplasma da Universidade Federal de Lavras (UFLA), quanto a reação ao Fusarium oxysporum f. sp. phaseoli e, ao mesmo tempo, estimar os parâmetros genéticos e fenotípicos que possam auxiliar em futuros programas de melhoramento para esse caráter. Foram avaliadas 367 linhagens em dez experimentos. As testemunhas 'Carioca' (suscetível) e 'Carioca MG' (resistente) foram utilizadas em todos os experimentos. O delineamento utilizado foi inteiramente ao acaso, com cinco repetições e parcelas de uma planta por vaso. As inoculações foram realizadas segundo a metodologia de corte e imersão de raízes na suspensão de esporos do fungo e as avaliações realizadas aos 21 dias após a inoculação com base no índice de severidade da doença empregando-se notas de 1 (plantas sem sintomas) a 9 (plantas mortas).Das linhagens do banco de germoplasma da Universidade Federal de Lavras (UFLA) avaliadas, 36,5 por cento foram resistentes ao Fusarium oxysporum f. sp. phaseoli. Entre as resistentes, a maioria foi linhagens obtidas antes de 1990. Das 18 linhagens dos experimentos de VCU, do período de 2005/06, apenas quatro foram suscetíveis. A estimativa da herdabilidade (h²) foi elevada (h² = 87 por cento), indicando que, a princípio, o caráter é de fácil seleção.

Among the pathogens that most contribute for reducing the productivity of beans in Brazil is the Fusarium oxysporum f. sp. phaseoli. The use of resistant cultivars is the most effective control for this pathogen. The aim of this study was to evaluate germoplasm bean (Phaseolus vulgaris L.) lines of the Federal University of Lavras (UFLA) as the reaction to the Fusarium oxysporum f. sp. phaseoli and at the same time, to estimate the genetic and phenotypic parameters that could help in future programs of improvement for this character. Three hundred and sixty seven lines were evaluated in ten experiments. The controls' Carioca'(susceptible) and 'Carioca MG'(resistant) were used in all experiments. The experimental design used was a entirely randomized one, with five replicates and plots of one plant per pot. The inoculations were carried out following the method of cutting and dumping of roots in the suspension of spores of the fungus and the assessments conducted at 21 days after inoculation based on the index of severity of the disease employing up notes of 1 (plants without symptoms) to 9 (dead plants). Among the lines of germoplasm bank of the Federal University of Lavras (UFLA) assessed, 36.5 percent were resistant to Fusarium oxysporum f. sp. phaseoli. Among the resistance, most of the lines were obtained before 1990: out of the 18 lines of the experiments of VCU evaluated in 2005/06, only four were susceptible. The estimate of heritability (h²) was high (h² = 87 percent), indicating that, in principle, the character is of easy selection.

Variabilidade genética associada à germinação e vigor de sementes de linhagens de feijoeiro comum / Genetic variability associated with germination and seed vigor of common bean lines

Objetivou-se, com este trabalho estimar a variabilidade genética para os caracteres relacionados com a velocidade de germinação e a capacidade das plantas em cobrir rapidamente o solo. Foram utilizadas sementes de 94 linhagens do banco de germoplasma de feijão (Phaseolus vulgaris L.) da Universidade Federal de Lavras, que diferiam em vários caracteres, tais como, cor, tamanho e formato das sementes. Foram realizados dois experimentos para avaliação das linhagens. O primeiro foi aos 120 dias e o segundo aos 360 dias após o início do armazenamento (em temperatura e umidade ambientes e sob baixa luminosidade). Foram obtidos as porcentagens de germinação ( por centoG), o índice de velocidade de emergência (IVE) e a matéria seca (MS). As variáveis foram padronizadas e obtido o somatório do IVE + MS. Foram obtidas as correlações fenotípica, genética e ambiental entre todos os caracteres e estimaram-se o ganho esperado com a seleção e a resposta correlacionada. Tanto a por centoG, quanto o IVE tiveram seus valores reduzidos na avaliação aos 360 dias após o armazenamento das sementes, em comparação com a avaliação realizada aos 120 dias. Foi possível obter ganho com a seleção, para maiores por centoG, IVE e MS. O maior ganho foi obtido no primeiro experimento. Entre as linhagens avaliadas há variabilidade suficiente para se proceder à seleção com relação à germinação e emergência. As linhagens JALO EEP 558, PI-103 e CVII 39-24 foram identificadas como as melhores em relação à germinação e emergência e as linhagens RP-2, BP-34 e ESAL 569 foram as que apresentaram menor vigor.

The objective of this study was to estimate the genetic variability for characters related with the germination rate and the capacity of the plants to occupy the ground quickly. Ninety four lines from the common bean (Phaseolus vulgaris L.) germoplasm from the Universidade Federal de Lavras, differing in several characters as color, size and shape of the seeds were used. Two experiments were carried out to evaluate the bean lines. The first was conducted at 120 days and the second 360 days after the beginning of storage (room temperature and humidity and under low light). Percentage of germination ( percentG), emergency speed rate (ESR) and dry matter (DM) were obtained. The variables were standardized and obtained the sum of the ESR + DM. Phenotypic, genetic and environmental correlations between all the characters were obtained and the expected gain was estimated with the selection and correlated response. Both the G percent and ESR presented reduced levels in the evaluation at 360 days after seed storage in comparison with the evaluation at 120 days. It was possible to obtain the gain with the selection, for higher percentG, ESR and DM. The higher gain was obtained in the first experiment. Among the lines evaluated, there are genetic sufficient variability to proceed the selection for germination and emergence. The lines JALO EEP 558, PI-103 and CVII 39-24 were identified as the best for germination and emergence and the lines RP-2, BP-34 and ESAL 569 were those with smaller vigor.

Controle genético da incompatibilidade do cruzamento entre cultivares andinas e mesoamericanas de feijoeiro comum / Genetic control of incompatibility in crosses of andean and mesoamerican common bean cultivars

Normalmente, ocorre incompatibilidade nos cruzamentos entre feijoeiros de origem andina com mesoamericanas. Há dúvidas no controle genético do caráter. Singh & Gutiérrez (1984) relataram que no controle do caráter estão envolvidos dois genes e ocorre epistasia recessiva dupla. Vilarinho (2004) apresentou resultados, relatando que não seriam apenas dois genes. Para melhor elucidar o controle genético desse caráter foi realizado o presente trabalho. Para isso, a cultivar de origem andina 'Jalo EEP 558' foi cruzada com a 'Small White', que é mesoamericana, porém compatível com a anterior. A cultivar de origem mesoamericana 'Mulatinho da Vagem Roxa' também foi cruzada com a 'Small White'. As gerações F1 desses dois híbridos foram cruzadas entre si. As sementes resultantes foram semeadas no campo e avaliada a ocorrência ou não da incompatibilidade. Constatou-se a segregação de três plantas normais para uma incompatível. Esse resultado evidencia que são dois genes, DL1 e DL2, e que o genótipo das cultivares envolvidas são: 'Jalo EEP 558' dl1dl1DL2DL2 ; 'Mulatinho da Vagem Roxa' DL1DL1dl2dl2 ; 'Small White' dl1dl1dl2dl2.

Crosses between Andean and Mesoamerican common beans are usually incompatible. There are doubts about the genetic control of the trait. Singh & Gutiérrez (1984) reported that two genes are involved in the trait control and that double recessive epistasis occurs. On the other hand, Vilarinho (2004) presented results indicating that more than two genes are involved. The present study was carried out to clarify the genetic control of this trait. For this purpose, the Andean cultivar 'Jalo EEP 558' was crossed with 'Small White', which is Mesoamerican, but compatible with the former one. The Mesoamerican cultivar 'Mulatinho da Vagem Roxa' was also crossed with 'Small White'. The F1 generation of these two hybrids was crossed with each other. The resulting seeds were sown on the field and the occurrence of incompatibility was evaluated. Segregation of 3 (normal) to 1 (incompatible) plants was observed, indicating that there are two genes, DL1 and DL2, as reported by Singh & Gutiérrez (1984), and that the genotype of the cultivars involved are: 'Jalo EEP 558' dl1dl1DL2DL2 ; 'Mulatinho da Vagem Roxa' DL1DL1dl2dl2 ; 'Small White' dl1dl1dl2dl2.

Envolvimento de agricultores no processo seletivo de novas linhagens de feijoeiro / Involving farmers in the selection of new common bean lines

Neste trabalho, objetivou-se o envolvimento de agricultores na seleção de novas linhagens de feijoeiro. Foram conduzidos 10 experimentos onde foram avaliadas nove linhagens melhoradas de feijão, juntamente com a cultivar BRSMG Talismã, em propriedades agrícolas com tradição na cultura do feijoeiro. O delineamento experimental foi o de blocos casualizados com três repetições e as parcelas de 10 linhas de 5m. Foram avaliadas, a severidade de mancha-angular, produtividade e solicitada aos agricultores a avaliação do tipo de grão. A linhagem OP-S-30 foi a que apresentou maior produtividade média nos 10 ambientes avaliados, tolerância a mancha angular e tipo de grão com boa aceitação de acordo com a opinião dos agricultores. Além dessa linhagem, a OP-S-16 e OP-S-80 também apresentaram desempenho superior. Os resultados obtidos evidenciaram que os agricultores e melhoristas têm muitos objetivos comuns com relação aos fenótipos desejáveis de uma cultivar de feijão para a região.

This work had the objective of involving the farmers in the selection of new common bean inbred lines. Ten experiments were carried out to evaluate nine inbreed lines and the commercial cultivar BRSMG Talismã in farm conditions of traditional common bean producers. The experimental design was a randomized complete blocks with three replications with plots of 10 rows of 5m each. Angular leaf spot severity and yield were evaluated and it was required from farmers to evaluate about the grain type. Inbred line OP-S-30 presented the highest mean grain yield in all environments, angular leaf spot tolerance and grain type with good acceptance according to the farmers. Besides the two inbred lines OP-S-16 and OP-S-80 presented higher performance. The results reinforced that the farmers and breeders really have very common objectives in relation to the desirable phenotypes for a common bean cultivar in the region.

Trinta e dois anos do programa de melhoramento do feijoeiro comum em Minas Gerais / Thirty two years of common bean breeding in Minas Gerais state

Conduziu-se este trabalho, com o objetivo de proceder à análise crítica do Programa de melhoramento genético do feijoeiro comum em Minas Gerais nos últimos 32 anos com ênfase nas implicações da interação linhagens x ambientes, além de avaliar se houve progresso genético. Para isso, foram utilizados dados de 169 experimentos conduzidos no período de 1974 a 2004 e que envolveram 16 locais e três safras. A média da cultivar Carioca, comum em todos os experimentos, foi utilizada como estimador do efeito ambiental e a média das cinco melhores linhagens sob avaliação de cada biênio, como efeito fenotípico. A diferença entre essas duas médias forneceu o desvio genético. O coeficiente de regressão linear entre desvio genético Y (variável dependente) e o biênio X (variável independente) forneceu a estimativa do progresso genético. As interações linhagens x safras e linhagens x anos foram, na maioria dos casos, significativas, contudo, suas contribuições para a variação total foram inferiores a de linhagens x locais. Desse modo, fica clara a necessidade de que os experimentos sejam conduzidos em um maior número de locais. O programa de melhoramento genético do feijoeiro da UFLA tem sido eficiente e tem obtido linhagens com menor risco de adoção.

The objective of the present work was to make critical analysis of the dry bean genetic breeding program in Minas Gerais in the last 32 years by lines x environments interactions and genetic progress evaluations. Data from 169 experiments conducted from 1974 to 2004 in 16 locations and three seasons per year were used. The average of the cultivar Carioca, test in all experiments, was used as indicator of environmental variation; and the average of the five best lines, under evaluation in each biennium, was used as indicator of phenotypic variation. The difference between these two averages was used as genetic deviation. Genetic progress was estimated by linear regression coefficient between genetic deviation Y (dependent variable) and biennium X (independent variable). The interactions among lines x seasons and lines x years were significant in most cases, however, their contributions to the total variation were inferior to the lines x locations. Thus, it was necessary to conduct experiments in a larger number of locations. The common bean breeding program at UFLA has been efficient and has selected lines with less risk for adoption for farmers.

Estimação dos componentes da variância fenotípica em feijoeiro utilizando o método genealógico / Estimation of phenotypic variance components in common bean by the pedigree method

A obtenção de informações a respeito do controle genético dos caracteres por meio de variâncias com associação aos métodos de condução de populações de feijoeiro tem sido uma estratégia pouco empregada, porém pode ser de grande auxílio aos melhoristas na tomada de decisões. Com esse objetivo foi utilizada uma população segregante proveniente do cruzamento entre as cultivares BRS MG Talismã e BRS Valente. O avanço das gerações foi realizado de acordo com o preconizado pelo método genealógico. Em F4:5 obtiveram-se 256 progênies que foram avaliadas na safra 'das águas' 2004/2005. As sementes de cada progênie foram colhidas em bulk originando as progênies F4:6, as quais foram avaliadas na safra 'das secas' 2005. Os caracteres avaliados foram produtividade de grãos e porte das plantas. Constatou-se que na produção de grãos por planta, a variância ambiental dentro da parcela foi o principal componente da variância fenotípica entre progênies. A variância genética aditiva foi predominante para a produção de grãos, enquanto que para o porte a variância genética de dominância foi expressiva.

Obtaining information referent to the genetic control of traits by the estimates of variance associated to breeding methods is not frequently used for bean crops, however these estimate can greatly help breeders to take decision. With this objective a segregating population derived from a cross between the cultivars BRS MG Talismã and BRS Valente was evaluated. The advance of generations was done according to the pedigree method. In the F4:5 generation were obtained 256 progenies that were evaluated during the 2004/2005 'rain season'. Seeds were harvested in bulks, generating progenies F4:6, which were evaluated in the 2005 'dry season'. There evaluated grain yield and plant habit. For grain yield per plant, the environmental variance within plots was the main component of the phenotypic variance among progenies. The additive variance was predominant for grain yield and the dominance variance for plant habit.

Linhagens de feijão (phaseolus vulgaris L.): composição química e digestibilidade protéica / Bean (Phaseolus vulgaris L.) lines: chemical composition and protein digestibility

O feijão representa a principal fonte de proteínas para as populações de baixa renda, todavia a digestibilidade dessas proteínas é relativamente baixa. Por isto, os programas de melhoramento genético vêm trabalhando em busca de novas linhagens com níveis protéicos mais elevados. Assim, com a finalidade de fornecer informações aos melhoristas, neste trabalho foram analisadas 21 linhagens de feijão (Phaseolus vulgaris L.), quanto à composição centesimal e mineral, digestibilidade protéica, compostos fenólicos e inibidor de tripsina. O delineamento experimental utilizado foi o inteiramente casualizado, com 21 tratamentos (linhagens) e três repetições. O teor de proteína bruta variou de 22,34 a 36,28 g/100 g de matéria seca (MS); o de fibra detergente neutro de 7,56 a 20,91g/100 g MS; o de extrato etéreo de 0,53 a 2,55 g/100 g MS e o de cinzas de 2,97 a 4,87 g/100 g MS. Os teores, em g/100 g MS, de P, K, Ca, Mg e S variaram de 0,45 a 0,72; 1,51 a 2,48; 0,03 a 0,28; 0,18 a 0,34 e 0,28 a 0,45, respectivamente. Já os teores de Cu, Mn, Zn e Fe, em mg/kg MS, variaram de 11,37 a 17,73; 14,93 a 28,90; 36,67 a 69,90 e 71,37 a 126,90, respectivamente. A digestibilidade protéica in vitro variou de 18,03 por cento a 48,32 por cento. Os teores de compostos fenólicos variaram de 0,28 a 1,08 mg de ácido tânico/100 g MS e os de inibidor de tripsina de 59,93 a 151,07UTI/mg MS. Entre as linhagens com maiores teores protéicos a "ESAL 569" (bege com rajas marrons) apresentou a maior digestibilidade protéica e também níveis consideráveis de minerais. A "P-180" (bege com rajas marrons) ficou entre as linhagens com teores mais elevados de proteína bruta e entre as de maiores digestibilidades, além de ter apresentado teores elevados para a maioria dos minerais. Não foi observada nenhuma relação entre a digestibilidade da proteína e os teores de compostos fenólicos e inibidor de tripsina.

Bean represents the main source of proteins for the low income populations, though the digestibility of those proteins is relatively low. Consequently, the programs of plant genetic breeding have been working on the search for new lines with higher protein levels. Thus, with the purpose of supplying information to the researchers, in this work 21 bean (Phaseolus vulgaris L.) lines were analyzed for the centesimal and mineral composition, protein digestibility, phenolic compounds and trypsin inhibitor. The entirely randomized experimental design was used with 21 treatments (lines) and three repetitions. All values were within the following ranges: 22.34 to 36.28g of crude protein/100g of dry matter (DM); 7.56 to 20.91g of neutral detergent fiber/100g DM; 0.53 to 2.55g of fat/100g DM and 2.97 to 4.87g of ashes/100g DM. The levels, in g/100g DM, of P, K, Ca, Mg and S varied from 0.45 to 0.72; 1.51 to 2.48; 0.03 to 0.28; 0.18 to 0.34 and 0.28 to 0.45, respectively. Regarding Cu, Mn, Zn and Fe, the levels in mg/kg DM, varied from 11.37 to 17.73; 14.93 to 28.90; 36.67 to 69.90 and 71.37 to 126.90, respectively. The in vitro protein digestibility varied from 18,03 percent to 48,32 percent. The levels of phenolic compounds varied from 0.28 to 1.08mg of acid tanic/100g DM and the one of trypsin inhibitor from 59.93 to 151.07 TIU/mg DM. Among the lines with higher protein contents, "ESAL 569" (beige with brown stripe) presented the largest protein digestibility and also considerable levels of minerals. "P-180" (beige with brown stripe) was one of the lines with higher crude protein contents and digestibilities, and also presented high levels for most of the minerals. No relationship between protein digestibility and the contents of phenolic compounds and trypsin inhibitor was observed.

Desempenho de familias do cruzamento entre linhagens de feijões andinos e mesoamericanos em produtividade e resistência a Phaeoisariopsis griseola / Performance of common bean families from cross between of andean and mesoamerica lines on grain yield and resistance to Phaeoisariopsis griseola

No Estado de Minas Gerais, tem sido constatado que as raças fisiológicas prevalecentes de Phaeiosariopsis griseola (Sacc.) Ferr. infectam predominantemente os feijões mesoamericanos. Os feijões andinos normalmente apresentam boa resistência. A introdução de alelos de resistência de cultivares andinas em cultivares mesoamericanas é uma boa estratégia na obtenção de cultivares adaptadas e resistentes a esse patógeno. Com esse objetivo foi realizado o cruzamento entre a linhagem ESAL 550 (grupo andino e resistente à mancha angular) x Carioca-MG (grupo mesoamericano e suscetível à mancha angular). Após a avaliação das famílias segregantes nas gerações F2:3, F2:4 e F2:5, foram selecionadas linhagens que associavam bom nível de resistência à P. griseola e grãos creme com rajas marrons porém, nenhum deles em condições de ter aceitação comercial.

In some regions of Minas Gerais State, prevalent physiological races of Phaeoisariopsis griseola (Sacc.) Ferr. infect mainly cultivars of Mesoamerican origin, but the Andean cultivars are resistant. The introduction of alleles for resistance of Andean cultivars in Mesoamerican cultivars is a good strategy to obtain adapted cultivars with resistance to this disease. With this purpose, the cross between ESAL 550 (Andean group and resistant to angular leaf spot) and Carioca-MG (Mesoamerican group and susceptible to angular leaf spot) was performed. After evaluation of the segregant families in generations F2:3, F2:4 and F2:5, some lines with high resistance to P. griseola and grain type far from market standard were identified.

Phenotypic recurrent selection in the common bean (Phaseolus vulgaris L) with carioca-type grains for resistance to the fungi Phaeoisariopsis griseola

The efficiency of recurrent selection was assessed in obtaining common bean (Phaseolus vulgaris L) plant lines resistant to the phytopathogenic fungi Phaeoisariopsis griseola. The base bean population was obtained from the partial diallel between seven lines with carioca-type grains and 10 sources of resistance to P. griseola. The plants most resistant to the pathogen were selected in the F2 (S0) generation of the populations (C-0). The best S0:1 plants that presented carioca-type grains were intercrossed to obtain cycle I (C-I). The same procedure was adopted to obtain cycles C-II to C-V. In each recurrent selection cycle, S0:1 progenies selected were also assessed in experiments carried out in Lavras, Brazil, always using as check the Carioca MG (susceptible to P. griseola) and Pérola (tolerant) cultivars. The response to selection for resistance to the pathogen was estimated from the general mean of the S0:1 progenies from each selective cycle compared to the susceptible check Carioca MG. The estimated gain was 6.4 percent per cycle and the indirect response in grain yield by selection for resistance to the pathogen was 8.9 percent per cycle. The variability detected among the progenies in the last selective cycles enabled the prediction of additional responses to recurrent selection.

Resposta diferencial de linhagens de feijoeiro ao nitrogênio / Differential response of breeding lines of common bean to nitrogen

Visando à identificação de linhagens de feijão que sejam tolerantes ao estresse de nitrogênio (N) e que também apresentem resposta positiva a esse nutriente, foram avaliadas 100 linhagens em presença e ausência de N em cobertura, em quatro ambientes. Em cada ambiente, foram dois experimentos distintos com e sem N, no delineamento látice triplo 10x10, sendo a parcela constituída de uma linha de três metros de comprimento. Utilizando a produtividade média de grãos, foi estimado o índice de eficiência de utilização de nitrogênio. Na média dos quatro ambientes, a produtividade de grãos obtida com N foi 12 por cento acima da obtida sem N. Decompondo o efeito de níveis para cada linhagem, em 77 por cento delas não houve resposta à adubação nitrogenada em cobertura. Assim, apenas 22 linhagens responderam positivamente à adubação nitrogenada e, entre elas, a eficiência na utilização de N variou de 11,3 a 18,3kg de grãos por kg de N aplicado.

It was evaluated 100 breeding lines of common bean in the presence and absence of N in cover in four conditions aiming at identifing the lines of beans which would be tolerant to nitrogen (N) stress and/or also responsive to this nutrient. In each condition there were two distinct experiments with and without N, in a 10 x 10 triple lattice design, being the plot constituted by a line with three meters of length. It was estimated the index of efficiency of nitrogen utilization, through the average grains yield. The obtained yield with N was 12 percent above the one without N, in the average of the four conditions. By decomposing the effect of levels for each line, in 77 percent of them there was no answer to the nitrogen fertilization in cover. This, only 22 lines positively responded to nitrogen fertilization and among them the efficiency of N utilization ranged from 11.3 to 18.3kg of grains per kg of applied N.

Performance of common bean families after different generations under natural selection

A segregant bulk population derived from a single cross between the Carioca MG cultivar and the ESAL 686 line was used to investigate whether the action of natural selection in the direction required by the breeders and the delaying line extraction would increase the chance of obtaining families with greater grain yield. The populations were advanced from F2 to F24 and obtained families F2, F8 and F24 from the plants. These families and their parents were assessed for grain yield (kg/ha) in Lavras-MG in three sowing seasons (July 2001, November 2001 and March 2002) in an 18 x 18 lattice design with two replications in the first sowing and three in the other two. The largest mean yield, regardless of sowing season, was among the families derived from the F24 plants. The frequency of superior families increased when line extraction was delayed to more advanced generations.

Prediction of seed-yield potential of common bean populations

Earliest possible prediction of seed-yield potential of autogamous crop populations increases breeding program efficiency by saving time and resources. Alternatives for obtaining seed-yield predictions were compared by evaluating four common-bean populations in F1 and F2 generations together with the parents. Mean components (m + a' and d) and variances were estimated. The potential of each population was predicted by using both these and the Jinks and Pooni (1976) procedure, which allows probability estimation of each population of originating lines surpassing a determined standard. Estimate efficiency was determined by evaluating performances of 62 F5:7 families from each population. Mean component m + a' estimates obtained for the F1 and F2 generations proved efficient in predicting seed yield of F7 generation lines as did d for estimate variance among F7 generation families. In addition, the Jinks and Pooni (1976) procedure proved efficient in early prediction of common bean population genetic potentials, especially when using the m + a' estimate

Natural selection and family X location interaction in the common (dry) bean plant

Natural selection takes place while advancing generations of segregant populations of self pollinating species by the population (bulk) method. There is evidence that it maintains the individuals with greater grain yield. The question arises whether natural selection preserves the individuals which are more adapted only to the environment where the generation advance occurred, that is, if it contributes to increasing the genotype x environment interaction in the family assessment. This study was carried out to check this hypothesis in the common bean plant using families derived from a segregating population from a cross between the Carioca MG x ESAL 686 cultivars. The segregating populations increase in homozygosity was obtained by the population (bulk) method until the F14 generation, in three distinct locations in Minas Gerais state: Lavras, Lambari and Patos de Minas. Forty-seven F14:15 families were randomly taken from the population in each location and later multiplied to obtain F14:16 families. These families were jointly assessed with three controls using a triple 12 x 12 lattice design in the three locations of generation advance in the wet season of 1998/1999. All the estimated parameters showed that while advancing segregant populations by the population (bulk) method, natural selection acted to preserve the individuals which are more adapted to the environment in which they were advanced